#ifndef HEADER_HMAC_H
#define HEADER_HMAC_H
#include <openssl/opensslconf.h>
#ifdef OPENSSL_NO_HMAC
#error HMAC is disabled.
#endif
#include <openssl/evp.h>
#define HMAC_MAX_MD_CBLOCK	128	
#ifdef  __cplusplus
extern "C" {
#endif
typedef struct hmac_ctx_st
	{
	const EVP_MD *md;
	EVP_MD_CTX md_ctx;
	EVP_MD_CTX i_ctx;
	EVP_MD_CTX o_ctx;
	unsigned int key_length;
	unsigned char key[HMAC_MAX_MD_CBLOCK];
	} HMAC_CTX;
#define HMAC_size(e)	(EVP_MD_size((e)->md))
void HMAC_CTX_init(HMAC_CTX *ctx);
void HMAC_CTX_cleanup(HMAC_CTX *ctx);
#define HMAC_cleanup(ctx) HMAC_CTX_cleanup(ctx) 
int HMAC_Init(HMAC_CTX *ctx, const void *key, int len,
	       const EVP_MD *md); 
int HMAC_Init_ex(HMAC_CTX *ctx, const void *key, int len,
		  const EVP_MD *md, ENGINE *impl);
int HMAC_Update(HMAC_CTX *ctx, const unsigned char *data, size_t len);
int HMAC_Final(HMAC_CTX *ctx, unsigned char *md, unsigned int *len);
unsigned char *HMAC(const EVP_MD *evp_md, const void *key, int key_len,
		    const unsigned char *d, size_t n, unsigned char *md,
		    unsigned int *md_len);
int HMAC_CTX_copy(HMAC_CTX *dctx, HMAC_CTX *sctx);
void HMAC_CTX_set_flags(HMAC_CTX *ctx, unsigned long flags);
#ifdef  __cplusplus
}
#endif
#endif
